1. Field of the Invention
The invention relates to a motor driving method and more particularly to a motor driving method and device utilizing both non-electrical and electrical power sources.
2. Brief Discussion of the Related Art
Due to global energy reserves and frequently shown warnings about energy crisis, currently, more and more researchers are looking for alternatives to finite energy resources such as oil and coal, for electrical power generation. Among the alternatives, the most popularly and widely used are solar and heat energy, applied to electrical power generation for various kinds of electronic devices and units.
FIG. 1 shows a DC fan device 10, including a motor 12 and a converter 11. The converter 11 receives and converts a non-electrical power source 13, such as solar or heat energy, to an electrical power so as to be inputted to and drive the motor 12, such that a DC fan device 10 is allowed to provide heat dissipation.
However, the converter 11 suffers low power conversion efficiency corresponding to circuit dimension, i.e. the power generated per unit dimension is limited, such that the rotational speed of motor 12 is limited and usually insufficient for requirements.